Crushing and grinding machine



Feb. 13, 1934. P. s. KNITTEL CRUSHING AND GRINDING MACHINE Filed June 29. 1929 2 Sheets-Sheet l Feb. 13, 1934. P. s. KNITTEL CRUSHING AND GRINDING MACHINE Filed June 29. 1929 2 Sheets-Sheet 2 INVVENTOR Pall] ,f. [02 z'ffa/ ATTORN Patented Feb. 13, 1934 UNITED STATES PATENT? OFFICE 1 Claim.

This invention relates to crushing and grinding machines, and has for its general object and purpose to provide certain improvements in a machine of the type shown and described in Patent No. 1,698,268, issued to me on January 8, 1929.

My patented machine which is generally characterized by a rotor having four series of grinding sectors spaced apart 90 and cooperating with the grinding grate produces eflicient results but in operation has certain disadvantages, particularly when operating upon such products as coal. These disadvantages consist principally in the fact that in such a machine having the four series of sectors, the power requirements for starting the machine in operation, especially under load, are excessive, and secondly, in the operation of the machine at high speeds, a partial vacuum is produced within the rotor chamber resulting in the creation of a strong air current or high windage which blows the fine coal dust out through the feed hopper and into the room. This is not only a great annoyance and injurious to the health of the workers, but may possibly result in an explosion of coal dust.

It is therefore an essential object and purpose of my present improvements to provide a crushing and grinding machine wherein the sectors of the rotor are so arranged and proportioned relative to the rotor velocity and diameter that the 30 above noted disadvantages will be entirely overcome, while at the same time the sectors will operate with high efficiency to break up the large lumps of coal or other material and grind the same to the required size for which the machine may be designed. To this end, in one practical embodiment of the machine, I provide the rotor with two sets or series of grinding sectors spaced apart 180 or on diametrically opposite sides of the rotor axis, and the intervening spaces between the rotor and the wall of the rotor case or housing being entirely uninterrupted, thus permitting of the free ingress and egress of air to and from said housing and preventing the creation of strong air currents. It is also evident that by the use of only two sets of grinding sectors, the weight of the revolving rotor is materially reduced resulting in a proportionate reduction in the power required for the operation of the machine and especially in overcoming the inertia of the rotor when starting under load.

It is also an important feature of one embodiment of my present invention to provide the machine with a bypass through which finished product may freely pass without necessitating the re moval of any of the parts of the machine.

In general, my present improvements provide a machine of this kind which combines the functions of the jaw crusher with the cylindrical grate type of machine.

With the above and other objects in view,the invention consists in the improved crushing and grinding machine, and in the form, construction and relative arrangement of its several parts as will be hereinafter more fully described, illustrated in the accompanying drawings, and subsequently incorporated in the subjoined claim.

In the drawings, wherein I have disclosed several simple and practical embodiments of the invention, and in which similar reference characters designate corresponding parts throughout the several views,-

Figure l is a vertical sectional view through a crushing and grinding machine constructed in accordance with one practical embodiment of the invention;

Fig. 2 is an end elevation of the machine partly in section, and

Fig. 3 is a side elevation illustrating a slightly modified form of the invention for the reduction of the material operated upon to particles of comparatively large size.

In the illustrated embodiments of the invention, I have shown the machine casing or housing 5 generally similar to that illustrated in my issued patent and with the upper open end of which, the usual feed hopper (not shown) is adapted to be connected. The bottom of the casing or housing 5 is also open and through the same the finer particles of the material passing through the grinding concave or grate 6 mounted in the lower part of the housing is discharged. At one end of this grate 6 a suitable breaker plate 7 is adjustably mounted in any suitable manner and extends into the upper part of the housing 5 and preferably is in contacting engagement at its upper edge with one end wail of said housing. The opposite end wall of the housing adjacent the other end of the grate 6 is provided with a suitably mounted gate indicated at 8 through which foreign materials such as pieces of metal and the like may from time to time be removed from the rotor chamber 9 of the machine.

The concave or grate 6 is concentric with the axis of the main shaft 10 of the machine, which is journalled at its opposite ends in suitable bearings indicated at 11. Upon the shaft 5 and with.- in the opposite ends of the chamber 9, the rotor heads indicated at 12 are suitably fixed. For the sake of lightness, these heads are preferably of skeletonized form, and in said heads the opposite ends of the rods 13 are suitably secured. As herein shown, four of these rods are provided in concentric relation with the shaft 10 and spaced apart 90. Between the rotor heads 12 a plurality of collars or hubs 14 are fixed upon the shaft 10 in closely abutting relation. Each of these collars has integrally formed therewith, a pair of quadrant shaped arms or plates 15 which are disposed in spaced parallel planes and ber.

project from opposite sides of the collar 14. The outer edges of these plates are preferably curved concentrically with the shaft 10 and the opposite ends of each plate is provided with the supporting bearings 16 which receive two of the rods 13.

Upon two of the rods 13 at diametrically opposite sides of the shaft 10, the two series of grinding sectors 17 are loosely engaged. These sectors are preferably approximately triangular shaped form as shown, having internal concave apices 18 providing bearing seats for engagement with the rod 13. No claim is herein made to the grinding sector per se, since substantially the same form of sector is described and claimed in my Patent No. 1,721,821, issued July 23, 1929.

In the operation of the machine as above described, the coal or other material to be operated upon is fed into the upper open end of the grinding chamber 9 and the rotary means including the two series of sectors 17 are revolved at high speed in the direction indicated by the arrow in Fig. 1 of the drawings. By properly proportioning the length of the three grinding edges of the sector 17 with respect to the diameter of the grinding chamber 9 and the velocity of the rotor, the larger lumps of material will be caught by the two series of sectors, which assume the position shown in Fig. 1 relative to the rods 13 by the action of centrifugal force, and crushed against the breaker plate '7. The series of sectors and this breaker plate thus act as the complementary parts of the pivoted jaw type of crusher. After this crushing action, and as the movement of the rotor continues, the smaller pieces are acted upon by the outer peripheral edges of the sectors 17 and ground upon the bars of the grate 6, the finely ground material passing between the grate bars into a suitable collecting receptacle below the casing 5, or is delivered to a transporting conveyer. In the embodiment of the machine as shown in Figs. 1 and 2, the

.material is crushed and ground to a size in which the individual particles approximate inch in diameter.

With the use of only two series of sectors arranged at diametrically opposite points of the rotor, there are no closed compartments formed within the grinding chamber as is the case when three or more series of such sectors are used. Therefore, no vacuum will be created within the chamber 9, the air between the two series of sectors merely revolving therewith, and no addi tional air being drawn into the grinding cham- Therefore, the creation of strong air currents in the rotation of the rotor at high velocity, which will blow coal dust upwardly through the hopper and into the room, is obviated. This not only eliminates waste of material, but also the annoyance and injurious effect of the presence of coal dust in the room upon the health of the workers, as well as the possibility of explosion. It will also be evident that by reducing the number of series of grinding sectors, the power required for the operation of the machine and especially in the starting thereof under load, will be considerably less than in the machines in the prior art using a greater number of series of the grinding sectors.

In Fig. 3 of the drawings, I have shown another embodiment of the invention, in which, at the side of the grinding chamber 9 opposite to the breaker plate 7, a section of the grate 6 is omitted, thus providing a bypass indicated at 20 through the machine. By stopping the operation of the machine with the series of sectors 17 in approximately the positions shown in dotted lines in Fig. 3, material fed to the machine which is already of the required size may fall downwardly by gravity through the bypass 20 without being operated upon by the grinding sectors. The larger lumps of material are operated upon by the sectors in the manner above explained In the illustrated example, the machine is designed to reduce the material to particles approximating one inch in diameter, and after being acted upon by the grinding sectors, the finished material is delivered from the machine through the bypass 20.

From the foregoing description considered in connection with the accompanying drawings, the

several illustrated embodiments of my present 4 improvements will be clearly understood. It will be seen that I have materially improved such machines as heretofore used in the art, by combining in a single machine the functions of both a pivoted jaw type of crusher and the cylindrical rotary type. By the reduction in weight of the rotor, the machine may be operated at very high speed with economical power consumption and increased production of the finished product. Also, it is apparent that the manufacturing cost of the new machine will be appreciably less than that of the prior art machine employing three or more series of the grinding sectors.

When advisable, due to wear or for other reasons, the two series of sectors 1'? may be removed from the rods 13 upon which they have been operating, and arranged upon the other pair of rods 13. Thus the machine may be inexpensively maintained at its highest operating eii'iciency.

In the foregoing description and the accompanying drawings, I have described and illustrated several forms of my invention, which have given excellent results in practice, nevertheless it is to be understood that my new machine as to the essential features thereof, might also be incorporated in various other alternative mechanical forms, and I accordingly reserve the privilege of resorting to all such legitimate changes in the form, construction and relative arrangement of the several parts as may be fairly considered within the spirit and scope of the appended claim.

I claim:

In, a machine of the character described, a grinding chamber having a top feed opening extending across the entire width thereof, rotary grinding means mounted within said chamber and consisting of only two series of grinding sectors spaced apart 180, said grinding chamber having a concave grate below said rotary means, and a breaker plate at one end of said grate extending above the axis of said rotary means, said grate at its other end terminating in spaced relation to the adjacent end wall of the grinding chamber and providing a bypass in line with the feed opening finished material may fall by gravity from said chamber, said series of sectors acting upon the larger lumps of material fed to said chamber to first crush the same against said breaker plate and subsequently grind the crushed particles upon the surface of said grate to the required size for passage through said bypass.

PAUL S. KNI'I'I'EL.

through which unground and 

